Walsh's contract offer expires as Dons wait on Mason and Brittain
The Welsh defender joined the club initially on loan from Crawley in early 2015 as Dons won promotion to the Championship, signing permanently at the end of the season.
"Joe Walsh will move on," Martin confirmed on Monday morning. "I had a chat with him and his agent and they're exploring other options still so the timeline has gone on that and I wish Joe all the best. He has been a top servant for the club, he's a top lap he's just decided to move on which is completely fine."
Called up to the Wales national squad on several occasions during his time, Walsh leaves for pastures new but there are still potential returns on the horizon for Callum Brittain and Joe Mason, with their deals will on the table.
Dons boss Martin said he was hopeful of getting Mason's deal inked by the end of the week, while he met with Brittain on Friday to discuss his future.
He said: "With Joe, talks are still ongoing. We hope that one will be resolved by the end of the week.
"With Callum, we had a really good chat with him on Friday, but we'll have to see what happens. He is a very good player and we expected there to be interest and there is in him. We'll have to wait and see but I'm hopeful he will be back with us, but we're prepared if he doesn't.
"We want players back, doing our work and we don't want them missing pre-season."